In order to meet the needs of an experimental model for human gonorrhea, we have developed the first model of acute gonorrhea in a convenient laboratory animal, the female mouse. We propose now to use this model for obtaining a better understanding of the pathogenesis and immune response in gonorrhea. Natural immunity will be investigated with special emphasis on local factors in the genital tract that determine initiation of infection. Acquired immunity will be examined from the point of view of mechanisms of recovery and resistance to reinfection in convalescent and systemically immunized animals. The information obtained in these studies could improve understanding of local resistance to venereal infection.